Difficulty in SLI diagnosis: a case study of identical twins.

This paper examines identical 12-year-old twins with language difficulties, one of whom falls into the diagnostic remit of SLI while the others does not due to IQ differences. Further diagnostic testing was carried out and their language was analysed to determine whether their diagnosis were reflected by different linguistic abilities. Results show a strong similarity in linguistic profiles, leading to a questioning of IQ use in SLI diagnosis.